Implications of CoGeNT and DAMA for Light WIMP Dark Matter

Abstract

In this paper, we study the recent excess of low energy events observed by the CoGeNT collaboration, and discuss the possibility that these events originate from the elastic scattering of a light (m_DM ~ 5-10 GeV) dark matter particle. We find that such a dark matter candidate may also be capable of generating the annual modulation reported by DAMA, as well as the small excess recently reported by CDMS, without conflicting with the null results from other experiments, such as XENON10. A dark matter interpretation of the CoGeNT and DAMA observations favors a region of parameter space that is especially attractive within the context of Asymmetric Dark Matter models. In such models, the cosmological dark matter density arises from the baryon asymmetry of the universe, naturally leading to the expectation that m_DM ~ 1-10 GeV. We also discuss neutralino dark matter from extended supersymmetric frameworks, such as the NMSSM. Lastly, we explore the implications of such a dark matter candidate for indirect searches, and find that the prospects for detecting the neutrino and gamma ray annihilation products of such a particle to be very encouraging.